Wall structures for electrolytic cells



Jan. 21,- 1958, J. SZECHTMAN 2,820,755

WALL STRUCTURES FOR ELECTROLYTIC CELLS Filed Nov. 4, 195a 2 SheetsSheet 1 INVENTQR. Jo SHUA Sz ECH TMA N ATTORNEY,

Jan. 21, 195% J. SZECHTMAN 2,820,755

WALL STRUCTURES FOR ELECTROLYTIC CELLS Filed Nov. 4, 1953 2 Sheets-Sheet 2 INVENTOR. JOSHUA ,SzEcHT/ /A N A 7 TORNEY.

United rates herein.

zszarss Patented Jan. 21, .1958

Fire

2,820,755 WALL STRUCTURES FOR ELECTRQLYT IC CELLS Joshua Szechtman, Byram, Cnn., assignor to Amroc Incorporated, New York, N. Y., a corporation of Michigan Application N0v'ember'4, 1953, Serial No. 390,194

5 Claims. (Cl. 204-219) This invention relates to electrolytic cells of the mobile mercury cathode type, and is particularly concerned with the wall structure of the primary section of such cells.

In mercury cells used for the electrolysis of alkali metal chlorides and for the production of chlorine gas, the primary section is usually constructed in the form of a long and narrow trough-shaped vessel. These vessels are normally slightly inclined with respect to the horizontal so that when in operation a thin film of mercury flows along the bottom of the section. Brine or other electrolyte flows on top of the mercury, and during the operation of the cell, wet chlorine gas is produced and collects in the space in the cell above the brine.

The bottom of the vessel, along which the mercury flows, is generally constructed of steel, but the faces of the sidewalls which come in contact with the brine and the chlorine gas must be constructed or lined with a material resistant to the corrosive action of the brine and of the wet chlorine gas. Hard rubber is normally employed for this purpose.

Various non-corrosive sidewall constructions have been devised for resisting this corrosive action. Principally, they have been concerned with the application of linings, commonly of hard rubber, to the sidewalls, which linings extend down below the brine level, to assure that neither the brine nor the chlorine can get beneath the lining and attack the wall in back of it. This is difiicult to do, and it is more difdcult still to prevent mercury from creeping past the edges of the lining. Depending on the cell construction, the mercury, due to its tendency to creep through small spaces, leaks out and drops on the floor, or seeps up under the linings. The loss of mercury in these manners can often go by unnoticed and explosions can result due to insutlicient mercury coverage on the bottom of the cell section or vessel.

The construction of the present invention obviates the foregoing and other drawbacks of prior constructions, and does so in a simple, strai htforward, fool-proof manner. The invention construction is designed to prevent anyrleakage of mercury past the walls of the cell, but should such leakage occur, the invention furnishes safeguards against any damage being caused. In fact, the invention construction not only provides for containing any mercury which may possibly leak outof the actual cell area, but'it also provides for the mercury which has leaked out forming a seal to stop continuation of the leakage.

The cell of the invention, besides being more efiective than those heretofore employed insofar as prevention of leakage and avoidance of the results thereof is concerned, is also of moreeconomical construction. Previous practices'have' renderedit necessary to accurately machine the edges of the bottom surface of the cells. The necessity of such machining, is obviated by the construction of the instant invention, for the type of edge-seal requiring such machining is no longer-needed. The mercury itself will tormasealif necessary.

The cellof the invention also'siniplifies repair and recost of such work. It is merely necessary to remove wall elements and renew the coverings on them or efi'ectother repairs to them when such becomes necessary. Heretofore, practically the whole trough had to be relined or replaced when-repairs to the linings were needed. Such is no longer the case. I p

It is accordingly the principal object of the invention to improve on the construction of the primary section-of electrolytic cells used in the production of chlorine.

Another object is to improve on the relationship between sidewalls and bottom of such cells.

Another object is to reduce the amount of machining necessary in forming such cells.

Still another object is to form a tight seal against the leakage of mercury from suchv cells.

A further object is to provide for thecatching and retaining of any mercury which maytpossibly leak fromrsuch cells.

And a still further object is to provide for the employment of mercury which may leak from such cells. to form a seal against any further leakage.

A still further object is to reduce the work. and ,expense involved in reconditioning such cells.

Other and more detailed objects willin part be obvious and in part be pointed out as the description of the invention, taken in conjunction with the accompanying drawing, proceeds.

In that drawing:

Figure l is a diagrammatic plan. view,ywith artransverse fragment broken away to save space, of a cell in accordance with the invention, illustrating the relationshipof the parts thereof.

Figure 2 is a half transverse section and a half end elevation of such a cell, on enlarged scale, with ,thecenter portion thereof broken away to save space anduillustrating the preferred embodiment of the invention.

7 Figure 3 is a view similarto thelefthand'portion ofEigure 2 illustrating one modification of. the invention; and

Figure 4 is a similar. view of another modification.

The primary cell section here being. considered would generally be in the form of an l-beam providingatrough between one pair ofends of the I, or. would beformedlto provide a similar solid trough-shaped channel. In the case of an I-beam, the web of the beam,,or in the case ofa trough-shaped channel, the bottom of thechannel, would serve as the bottom of the vesselalongwhich the mercury flows. The cell of the invention asillustrated' is shown as being formed from an I-beam section, but it is of course to be understood that such is for illustrative and not limiting purposes. The base of the troughis shownat 1 in Figure 2, and the integral upstanding sides thereof,

hereinafter for convenience referred to as side rails are shown at 2 and 3. It isof course to be understood that the cell is long and narrow, and asection has be en broken away across the cell in Figure l to illustrate this. Also the width of the cell is substantially greater than is shown in Figure 2. There a center section has been broken away since it is not needed for an understanding ofthe invention.

in the- Figure 1 showing, the cell{ is indicated-asclosed atits ends 4 and 5. The end 4 extends into ,anlendlbOx 6 which serves for the introduction of the mercuryrinto the cell, while the box 7 at the other end enables depleted brine and mercury which has picked up some amalgam to flow out into the secondary section. These features form no particular part of the instant invention, so no further discussion of them is necessary.

Reverting to Figure 1, it will be seen that the cell' is provided with a pair of sidewalls 8 and 9 which are spaced ing.

In the first place, the sidewalls 8 and 9 as shown, are formed as U-shaped members having a base 10 which forms the vertical wall, top and bottom flanges 11 and 12, and end flanges 13 and 14. The top flange 12, as here shown, has a right angle bracket 15 applied thereto, which bracket has an upstanding portion 15' inset from the face of the wall 10 for the reception and seating of a cover tobe hereinafter described. The inner surface of the wall 10, being the one on the side of the brine and gas in the cell, is faced with a hard rubber covering This covering commences at 17 underneath the flange 11' and extends all the way up the surface of the wall 10 as seen at 16. The covering turns inwardly along the flange 12 at 18, extends up the portion 15, and is' beaded around the end thereof at 19. This rubber covering is suitably secured to the steel of the rail member to adhere tightly thereto.

A gasket strip 20, preferably of softer material than the wallcovering 1617,is located" between the portion 17 and the upper surface 21 of the base 1 of the cell This strip runs full length of the sidewall, as does the' hard rubber wall covering.

, The'bottom flange 11 is perforated at closely spaced positions 22 along its length to receive studs 23. The studs 23 are preferably welded to thebase 1, though they may be otherwise suitably secured thereto. Ex- I tending up through the gasket 20,'the covering 17 and 2 the perforations 22. they receive washers 24 and nuts 25 for clamping the flange l1 and cover portion17 against the gasket 20. When all of the nuts22 aretightened down, a seal is provided againstleakage of mercury on the surface 21 outwardly of the walls 8 and 9.

. In the unlikely event that the seal formed by the gasket material 20 should fail and any mercury should thus leak .out to the position 26, protection would be aiforded against loss of mercury and against possibleexplosions due to insuflicient mercury covering the bottom 21. This Yprotection would be effected by the mercury which first leaks out since thatportio-n could not escape beyond the side rail 2 so would collect at the position 26. The leaking mercury would thus build up at the position 26, or in the trough like chamber provided between the inner surface 27 of the side rail 2 and the opposed portions of the sidewall with its covering material. Once the mercury at the position 26 has built up sufficiently to equal the level ofmercury on thesurface 21, the part that had leaked out would serve as a seal against further leakage of mercury. Since mercury iscontin'uously flowing over the surface 21 and is replenished from the secondary cell, the level on the surface 21 will be retained.

Should the gasket material 20 or any of the covered hard rubber 16, 17, 18 fail in any respect, itlwould merely be necessary to remove the side rail and replace the defective covering layer or gasket. Furthermore, this construction has thesubstantial advantage vof rendering unnecessary the careful machining of the base of the cell, and particularly the position where the base joins the sidewall, which heretofore had to be most accurately formed to receive the lower end of the sidewall cover- The cell as lieresliownis provided with a cover 28 seated on the hard rubber portion 18 and sealed along its side by means of a gasket 29 and a liquid seal 30. This, howeveryis merely provided to complete the i1lustration and forms no particular part of the instant invention since covers of various other forms could be applied. Suitable flanges 3'1 and 32 are provided for, securing the ends such as 4 and in place on the cells. Those ends are provided with hard rubber coverings like the covering 16 where they are exposed to the brine or'gas.

The brackets 33 are illustrated for the partial mounting of the cell but, in and of themselves, they form no particular part of the invention.

An alternate form of sidewall construction and clampgasket 50 and sidewall 42 on the constructions disclosed. It is of course to be understood the top 43. A relatively soft gasket. 50 is seatedon the bottom surface 51-of the .cell andv is engaged .by the portion 47 of the hard rubber liner. t

A tight joint is formed in the region of the gasket 50 by means of the bolt 52 whose head engages theu'pper surface 53 of the portion 43 and whose shank passes down through the perforation 54 so that the threaded portion 55 of the bolt is in threaded engagement with the opening in a mounting rail 56. The mounting rail 56 is preferably welded at 57 to the inner surface 58 of the side rail 41 and extends along the full length of that side rail. The bolts 52 are closely spaced along the portion 53 of thesidewall like'the bolts 23 of Figures 1 and 2. Thus,

when the bolts 52are turned down they carry, the sidewall 42 down with them to'compress the'gasket 50 and make a tight seal'beneath the wall along the length there of.

Again,-should the gasket 50 fail, themercury which leaks past it would be trapped at 59in the trough like chamber between the side rail 58 on one 1hand and"the other hand. As in the previous form, this mercury could not escape, but would build up and thus form an effective seal. Removal of the sidewall and'replacement of the same, as well as that of the gasket 50, can be easily eifected when desired, andthe need for fine machining ofany portion of the surface 51 is eliminated.

A further modified clamping arrangementis illustrated in Figure 4 where again a fragment of an Lbeam construction is shown as the basic element. This construetion provides a cellbase 60 and side rails 61 fromwhich a mounting rail 62 projects, being welded at '63,.as is the rail 56 in the :Figure 3 form. Here, however, the bolt 64 is in threaded engagement with the mounting rail 62 ,at the position 65. The bolt 64 is thus screwed down through the mounting rail 62 and has its bottom end 66 engaged with the upper surface of an L-clamp 67.,

The'horizontalportion of the L-clamp'67 engages the horizontal outwardly extending portion 68. of the sidewall 69 to force thesame downward. The downward extend ing portion 70 of the clamp plate 67 engagesat 71 with the curved corner between the bottom 72 of the cell and the inner wall 73 of the side rail 61. Thus the clamping force is directed against the sidewall portion 63. v 7

Again, the sidewall 69 is suitably covered Witha hard rubber covering 73 which extends down around portion 68 at 74 and terminates at 75 in an upturned portion lying against the outer end surface of the portion 68. A suitable gasket 76 is provided between the hard rubber portion 75 and the bottom 72 of the cell.

The gasket 76 extends along the'whole length of the sidewall, as does the clamping plate 67. The bolts 64 are positioned. in spaced relation along the lengthof. the cell like the bolts 23 and 52jpreviously described. 7 Thus, when the bolts 64 are turned down against the clamping plate 67,the latter engages the upper surface of the wall portion 68,and squeezes the gasket 76 as well as the hard rubber portion 74 to provide a tight seal.

A ain, should the gasket 76 or the, portion 74 fail, the mercury will ieak'into and be caught in the trough-at the position 77 where it will build up until it provides a hydrostatic seal against further leakage. ii a f From the foregoing description of the-preferred and alternate embodiments of the invention, it will'be appreciated that-the objects thereof are achieved by the novel that the specific wall structures illustrated are shown for illustrative and not limiting purposes, since one skilled in the art would appreciate how different wall structures and different manners of clamping the same in position could be devised without departing from the spirit or scope of the invention. Speaking more generally, it is obvious that certain changes may be made in the constructions above described, and further embodiments of the invention could be made without departing from the scope thereof. It is thus intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In electrolytic cell conconstruction, an integral onepiece elongated steel member of U shape in cross section providing a base with a pair of upstanding side rails extending therealong, the upper surface of said base between said side rails lying substantially in a single plane and being devoid of recesses, individual side walls carried by said base within said rails, extending upwardly from said surface and extending substantially parallel with respect to said rails, resilient gasket means extending between the bottom ends of said side walls and said surface, and clamping means acting between said member and said side walls and engaging said side walls to secure said side walls in place, force the same towards said planar upper surface and to compress said gaskets, said side walls being in spaced relationship with respect to said side rails and cooperating with said side rails and with the included portions of said upper surface to form elongated troughs.

2. In electrolytic cell construction as in claim 1, said clamping means including bolts secured to said upper surface and extending upwardly therefrom, and means on said side walls for receiving said bolts.

3. In electrolytic cell construction as in 1, said clamping means being carried by said side rails and engaging projections on said side-walls.

4. In electrolytic cell construction as in claim 1, said clamping means including clamping plates engaging portions or said side walls and clamping members carried by said side rails and engaging said clamping plates.

5. In electrolytic cell construction as in claim 1, said clamping means including laterally extending flanges carried by said side walls and clamping members carried by said side rails and engaging said laterally extending flanges.

References Cited in the file of this patent UNITED STATES PATENTS 1,420,211 Paulus June 20, 1922 2,502,888 Ravenscroft Apr. 4, 1950 2,503,337 Hirsh Apr. 11, 1950 2,542,989 Carter Feb. 27, 1951 2,545,376 Ornhjelm Mar. 13, 1951 2,649,411 Shaw Aug. 18, 1953 FOREIGN PATENTS 667,477 Great Britain Mar. 5, 1952 

1. IN ELECTROLYTIC CELL CONCONSTRUCTION, AND INTEGRAL ONEPIECE EIONGATED STEEL MEMBER OF U SHAPE IN CROSS SECTION PROVIDING A BASE WITH A PAIR OF UPSTANDING SIDE RAILS EXTENDING THEREALONG, THE UPPER SURFACE OF SAID BASE BETWEEN SAID SIDE RAILS LYING SUBSTANTIALLY IN A SINGLE PLANE AND BEING DEVOID OF RECESSES, INDIVIDUAL SIDE WALLS CARRIED BY SAID BASE WITHING SAID RAILS, EXTENDING UPWARDLY FROM SAID SURFACE AND EXTENDING SUBSTANTIALLY PARALLEL WITH RESPECT TO SAID RAILS, RESILLIENT GASKET MEANS EXTENDING BETWEEN THE BOTTOM ENDS OF SAID SIDE WALLS AND SAID SURFACE, AND CLAMPING BOTTOM ENDS OF SAID SIDE WALLS AND SAID SURFACE, AND SIDE WALLS AND ENGAGING SAID SIDE WALLS TO SECURE SAID SIDE WALLS IN PLACE, FORCE THE SAME TOWARDS SAID PLANAR UPPER SURFACE AND TO COMPRESS SAID GASKETS, SAID SIDE WALLS BEING IN SPACED RELATIONSHIP WITH RESPECT TO SAID SIDE RAILS AND COOPERATING WITH SAID SIDE RAILS AND WITH THE INCLUDED PORTIONS OF SAID UPPER SURFACE TO FORM ELONGATED TROUGHS. 